The body of Salisbury resident Dennis Hitchcock, found slumped in a boat throttling in circles in a river near Crisfield, is at the office of the Maryland Medical Examiner for an autopsy, authorities confirmed Saturday morning.

Hitchcock, 64, was unresponsive on a 16-foot boat turning in circles near the mouth of the Little Annemessex River when authorities reached him about 2 p.m. Friday, according to the Maryland Natural Resources Police.

Candy Thomson, a NRP spokeswoman, said there are no preliminary indicators of foul play or intoxication, although confirmation would be based on autopsy findings expected as early as Monday, and a subsequent toxicology report that could take up to eight weeks.

“The body is up there now, and I assume an autopsy will be done this weekend if it is not too backed up,” Thomson said Saturday morning. “There is nothing to indicate anything out of the ordinary. He was slumped over. There is nothing in our report to indicate what he was doing.”

The NRP is the investigating agency in the case. The Coast Guard oversaw the boat rescue.

The incident brings to 16 the number of water-related deaths this year investigated by NRP, Thomson said. The total does not include the two swimmers that drowned recently in Ocean City, as those deaths were not investigated by NRP.

A significant number of them did involve boater intoxication, Thomson said, although she added that “there was nothing in the report” involving Hitchcock “to indicate alcohol” or other substances.

“Traditionally, that is one of the leading causes of death on the water in Maryland and nationally,” she said. “July is typically the busiest month for water fatalities.”

A Coast Guard spokesman said Saturday that fishing rods were on the boat when the rescue crew arrived, although Thomson could not confirm the victim had gone fishing.

A passerby alerted the U.S. Coast Guard of a boat “doing circle in the water with one person aboard unconscious,” according to a Coast Guard report.

A Coast Guard crew on a 29-foot response boat from the Crisfield station responded, using heaving lines to stop the vessel. A petty officer then climbed aboard and attempted to revive the victim, the report said.

Hitchcock was transported by an awaiting ambulance at the City Dock in Crisfield, and was pronounced dead at McCready Memorial Hospital, according to NRP.

Thomson said Hitchcock’s boat circled repeatedly because the unmanned vessel, apparently making turn, “clearly did not have an activated kill switch” that could have shut down the engine.

“Throttles are not spring-loaded, so they don’t go back to neutral position unless the operator has a kill switch,” she said. “The boat will keep going until it hits something, or runs out of gas. If you jerk the kill switch, it will stop.”